Multiple deletions of mitochondrial DNA are associated with the decline of motility and fertility of human spermatozoa

Sperm motility is one of the major determinants of male fertility and is required for successful fertilization. In a previous study, we demonstrated that the occurrence and accumulation of the 4977 bp deletion of mitochondrial DNA (mtDNA) is associated with diminished fertility and motility of human spermatozoa. The possible relationship between multiple deletions of mtDNA and the decline of fertility and motility in human spermatozoa was further explored in 36 subjects including subfertile and infertile males in this study. Using long- range polymerase chain reaction (PCR), we confirmed the 4977 bp deletion and identified two novel deletions of 7345 and 7599 bp of mtDNA in the spermatozoa with poor motility. We used Percoll gradients to fractionate spermatozoa with differing motility, and then screened for two novel large-scale deletions of the mtDNA. The results showed that the ratio of the deleted mtDNA in the spermatozoa with poor motility and diminished fertility were significantly higher than those in the spermatozoa with good motility and fertility. In addition, we found that the frequencies of the three large-scale deletions in the spermatozoa from patients with primary infertility and oligoasthenozoospermia were higher than those of the fertile males. Our findings suggest that mtDNA deletions may play an important role in some pathophysiological conditions of human spermatozoa.      

晚期脊髓损伤患者胚胎嗅鞘细胞移植后的电生理评价

目的:采用客观的电生理检查手段评价胚胎嗅鞘细胞移植治疗晚期脊髓损伤的有效性。方法:①对象:选择2003-02/2005-01北京市西山医院暨北京康复中心神经外科收治的接受人胚胎嗅鞘细胞移植治疗的晚期完全性脊髓损伤患者199例,男164例,女35例,平均年龄(34.7±11.3)岁,平均病程(4.7±5.5)年;受伤节段:颈段99例,胸段89例,胸腰段11例;受伤原因:车祸、摔伤、医源性损伤、机器挤压伤等。4个月流产胚胎由北京市虹天济神经科学研究院协作医院提供,产妇及其家属均签署知情同意书,实验经医院医学伦理委员会批准。②方法:取人胚胎嗅球,消化成单个嗅鞘细胞后培养2周。199例晚期完全性脊髓损伤患者均接受人胚胎嗅鞘细胞移植治疗,在全麻下行脊髓损伤节段后方入路,切开硬膜,显露出病变脊髓。分上下两点各注入50μL嗅鞘细胞悬液,细胞数共约1×106个。术后给予止血、抗感染等处理,未使用任何免疫抑制剂。③评估:移植前后分别采用肌电/诱发电位仪检查肌电图和椎旁躯体感觉诱发电位,每例患者检查2次,时间一致,且由同一医生操作。肌电图即检查患者大力收缩时的肌肉情况,以观察运动单位电位的数量、波幅及持续放电能力。椎旁躯体感觉诱发电位是于中线旁开2cm处两侧同时给予刺激,刺激强度以引起可见的肌肉抽动为准,在头皮上记录电位。方波刺激频率3Hz,强度20～40mA,时限0.2ms,观察感觉平面下降情况。结果:199例晚期完全性脊髓损伤患者均进入结果分析。①术后肌电图检查:93例(46.7%)显示部分受累肌肉大力收缩时募集波型改善,运动单位电位数量增加;105例(52.8%)无变化,1例(0.5%)比术前差。②椎旁躯体感觉诱发电位检查:90例(45.2%)显示感觉平面下降,其中左侧平均下降(1.9±1.2)个节段,右侧平均下降(2.0±1.2)个节段;107例(53.8%)无变化,2例(1.0%)双侧感觉平面上升。结论:对于胚胎嗅鞘细胞移植治疗晚期脊髓损伤患者,肌电图和椎旁躯体感觉诱发电位这两种电生理检查能较为客观的反映脊髓术后感觉和运动功能恢复情况。     

Breastfeeding challenges and opportunities during COVID-19 in Hong Kong

Barriers to sustain breastfeeding could be time and place specific. Here, we summarise new and old challenges to breastfeeding during COVID-19 pandemic in Hong Kong, some of which were obtained from qualitative in-depth interviews with health-care professionals. We document how unnecessary massive mother–baby separations in hospitals and doubts in COVID-19 vaccine safety seriously harm breastfeeding. We also discuss how the trends and increase in acceptance of receiving post-natal care from family doctors, online-antenatal class, work-from-home policy and telemedicine implicate new strategies to protect, promote and support breastfeeding during and after the pandemic. The challenges from the COVID-19 pandemic on breastfeeding have revealed new opportunities to support breastfeeding in Hong Kong and similar settings where exclusive breastfeeding for 6 months is still not the norm.     

Cooling and immunomodulation for treating hypoxic‐ischemic brain injury

Therapeutic hypothermia is now well established to partially reduce disability in term and near‐term infants with moderate‐severe hypoxic‐ischemic encephalopathy. Preclinical and clinical studies have confirmed that current protocols for therapeutic hypothermia are near optimal. The challenge is now to identify complementary therapies that can further improve outcomes, in combination with therapeutic hypothermia. Overall, anti‐excitatory and anti‐apoptotic agents have shown variable or even no benefit in combination with hypothermia, suggesting overlapping mechanisms of neuroprotection. Inflammation appears to play a critical role in the pathogenesis of injury in the neonatal brain, and thus, there is potential for drugs with immunomodulatory properties that target inflammation to be used as a therapy in neonates. In this review, we examine the evidence for neuroprotection with immunomodulation after hypoxia‐ischemia. For example, stem cell therapy can reduce inflammation, increase cell survival, and promote cell maturation and repair. There are also encouraging preclinical data from small animals suggesting that stem cell therapy can augment hypothermic neuroprotection. However, there is conflicting evidence, and rigorous testing in translational animal models is now needed.     

Clinical evaluation of an international static image–based telepathology service

Telepathology is the use of telecommunications technology as a means to facilitate transfer of image-rich pathology data between remote locations for the purposes of diagnosis, education, and research. Although varying levels of technology exist to accomplish this task, static image--based systems are currently the most widely used around the world. Field selection and image quality have often been identified as major impediments to the successful use of static images for diagnostic telepathology. Between November 1994 and July 1999, the Armed Forces Institute of Pathology (AFIP) performed electronic consultation on over 1,250 static image--based cases, recording a clinically significant concordance rate of 97.3% between telepathology and final diagnosis (in cases in which follow-up material was available). For the same subset of cases, an absolute concordance rate of 73.7% was attained. A review of the case flow and construction of the AFIP telepathology system is presented, as well as factors that have an impact on the diagnostic accuracy of static image-based telepathology sytems in general.     

Telecytology: Intraobserver and interobserver reproducibility in the diagnosis of cervical-vaginal smears

Telecytologic diagnosis of cervical-vaginal smears is potentially useful because it could allow more efficient use of cytopathologist resources and expertise. A pathologist in one location could, in principle, review cytotechnologists' findings using a video display hundreds or thousands of miles away. Currently, bandwidth restrictions limit practical implementation of such a system to review of fields that had been selected for review by the cytotechnologist. The purpose of our investigation was to evaluate how well this type of review correlates with a review in which the entire slide is available for examination by the pathologist. We prospectively selected 100 consecutive cervical-vaginal smears over an 11-day period in August 1999. For each smear, 4 to 12 fields containing abnormal cells from each slide were digitally imaged. Each of 3 pathologists reviewed all digitized images and all glass slides. Diagnoses based on selected digitized images were compared with those based on conventional pathologist review. The kappa statistic, a measure of chance-corrected agreement (reproducibility), was calculated in each setting. Overall, intraobserver and interobserver reproducibility of cervical-vaginal smear diagnoses is fair to excellent. The use of remote digital images for pathologist review did not introduce large (2-step) diagnostic disagreements. The disagreement between a pathologist's glass slide and digital diagnoses is less than that for different pathologists reviewing glass slides, although interobserver differences were even greater in the interpretation of digital images.     

Characteristics of a telecytology consultation service

Although numerous reports describe the application of remote video microscopy to pathologic diagnosis (telepathology), only a few address some of the special issues surrounding remote cytologic diagnosis (telecytology). These studies have generally suggested a high correlation between telecytologic diagnoses and those arising from direct examination of the glass slides, but factors affecting the clinical utility of routine cytologic diagnosis have not been examined. In this report, we describe our experience in telecytologic consultation on 99 cases seen at the Armed Forces Institute of Pathology between October 1995 and November 1999. The mean time between receipt of the telecytologic images and the contributor receipt of the faxed report was 9.9 hours (median, 5.13 hours). Using stringent criteria for agreement, we find fair to good (48%) concordance between the contributor's impression and the consultant's opinion. The concordance between the consultant's telecytologic diagnosis and the subsequent glass slide diagnosis is imperfect; in 8 (31%) of 26 cases in which the glass slide was sent after the telecytology consultation, a minor discrepancy between these diagnoses was found. No major discrepancies were found between the consultant's telecytologic and glass slide diagnoses.     

管花肉苁蓉化学成分的研究

目的：研究国产管花肉苁蓉的化学成分。方法：采用各种色谱技术包括HPLC分离化学成分,根据理化性质和波谱数据鉴定结构。结果：分离得到4个环烯醚萜苷、1个木脂素苷和1个单萜,分别为五福花苷酸(Ⅰ),8-表马钱子酸(Ⅱ),京尼平苷酸(Ⅲ),玉叶金花苷酸(Ⅳ),丁香树脂酚葡萄糖苷(Ⅴ)和8-羟基香叶醇(Ⅵ)。结论：化合物Ⅰ和Ⅵ为首次从本属植物中分离得到,化合物Ⅲ,Ⅳ和Ⅴ为首次从本植物中分离得到。     

Short and long term outcome of neonatal hyperglycemia in very preterm infants: a retrospective follow-up study

Background  

Hyperglycemia in premature infants is associated with increased morbidity and mortality, but data on long-term outcome are limited. We investigated the effects of neonatal hyperglycemia (blood glucose ≥ 10 mmol/l, treated with insulin for ≥ 12 hours) on growth and neurobehavioral outcome at 2 years of age.